In recent years, polymer-modified cementitious waterproof coating composition have been readily applied in the field of building and construction, as these coatings are environmental-friendly, and combine the flexibility of a polymer and the rigidity of a cement. These coating composition are often applied onto concrete surfaces to protect the concrete surfaces from water-related deteriorations.
U.S. Pat. No. 4,392,335 discloses a repair overcoating for concrete, stone, bricks and tile and even asphalts. The overcoating consists of multiple layers and each layer is bonded to the adjacent layers. For example, several embodiments of U.S. Pat. No. 4,392,335 include an adhesive epoxy intermediate underlayer that forms a bond with the base material and an overlying layer of flexible cementitious polymer material that are bonded to the underlayer. Epoxy resins are added in each layers, and hardening catalysts and solvents are arranged to increase bonding effectiveness. Usually, it is preferred to seal the upper surface of the cementitious layer with a thin coat of an epoxy sealer incorporated by ultraviolet protection additives.
U.S. Pat. No. 5,162,060 discloses a coating composition that includes synthetic polymer latex having uriedo functional groups, an amine-functional epoxy curing agent, a liquid epoxy resin, and a hydraulic cement.
U.S. Pat. No. 4,249,950 discloses an improved flexible cementitious material which is prepared by mixing an aqueous dispersion or latex of elastomeric polymer (e.g. butyl rubber) with cement (e.g. Portland cement), allowing the mixture to harden typically for 28 days under conditions of high relative humidity, and thereafter compressing the hardened material (e.g. by passing the material between rollers) to reduce the brittleness and to increase the flexibility thereof. The initial cementitious mixture preferably contains additional components such as a desiccant (e.g. lime). The resulting flexible material is useful as joint filler between concrete structures to take-up deformation therebetween.
U.S. Pat. No. 9,302,448 discloses a floor crack isolation system consists of a membrane and a deformable adhesive. The membrane includes a basemat and a flexible coating applied onto the basemat. The basemat has at least three plies; a ply of a meltblown polymer sandwiched between two plies of spunbond polymer. The flexible coating has a cementitious hydraulic component, a water-soluble, film-forming polymer and water. The finished membrane is flexible and is bonded to a subfloor with a deformable adhesive. U.S. Pat. No. 9,067,383 also discloses a flexible and rollable cementitious membrane for use as an underlayment based on the same waterproofing system via similar formula and manufacturing process.
U.S. Pat. No. 6,455,615 discloses a flexible polymer modified waterproof cement materials which can be used on a substrate or in concealed areas of construction engineering, water conservancy projects, municipal works. The waterproof material is made by kneading hydraulic cement, a polymer dispersion, a water-soluble polymer or re-dispersible resin and water. The kneaded material is mixed with cement and a toughening polymer at a weight ratio of about 100:10 to about 100:50, and then is calendared into sheets. These materials can adhere to dry or wet substrates firmly using the suitable adhesives. After application, the waterproof structure formed can bear retractive stress and deformation of the base or can resist outer impact. The water impermeability performance is shown to be only 0.3 Mpa for 90 minutes, tensile strength is about 1.5 MPa without nonwoven fabric mesh, and the elongation at break ranges from 80% to 240%.
U.S. Pat. No. 7,468,154 and U.S. Pat. No. 7,347,895 disclose a composition for making flexible articles which includes a hydraulic component of at least 50% by weight of fly ash, a water-soluble, film-forming polymer and water.
U.S. Pat. No. 7,784,542 and U.S. Pat. No. 8,598,093 disclose methods and compositions that may comprise cement, a nano-particle, latex, and water. The embodiments of the present invention include a cement composition and a method of allowing the cement composition to set in the subterranean formation. Although these resulting polymer cementitious films or sheets are flexible, accompanying drying shrinkage, the waterproof layer may crack or delaminate from the undercoated surface.
U.S. Pat. No. 8,931,228 discloses a waterproofing membrane that comprises a carrier sheet, a pressure sensitive adhesive layer on one surface of the carrier sheet, and a protective coating layer on the adhesive layer. The protective coating layer is highly reflective and operative to bond to concrete cast against it. Preferably, the protective coating layer comprises cement, polymer, and white pigment, and may optionally include filler, UV absorber and antioxidant. The protective coating layer protects the membrane against weather exposure, tolerates foot traffic and strongly adheres to concrete cast against it. U.S. Pat. No. 9,133,612 also discloses a waterproof membrane comprising a carrier sheet, a pressure sensitive adhesive layer, a protective coating layer, and a highly releasable bonding layer.
There is a need for a coating composition that forms a coat with high flexible, adhesion, waterproof and mechanical properties for construction surfaces.
Citation or identification of any reference in this section or any other section of this application shall not be construed as an admission that such reference is available as prior art for the present application.